This invention relates to new and useful improvements in methods of and apparatus for treating or completing and operating wells, either when the well is initially completed or when the well is completely reworked, and for treating the well after completion, if desired.
Heretofore, in installations in which an upper tubing section was removably connected to the upper end of a lower flow conductor left in place in a well and wherein a safety valve was run into the well on such upper tubing section, each of such upper flow conductor sections was separately installed and anchored in flow communicating connection with the upper end of a selected one of the lower tubing strings or flow conductors and was separately disconnectable therefrom and separately removable.
In addition, separate overshot connectors were carried on the lower end of each of the upper tubing sections and telescoped over the upper ends of the lower flow conductors left in place in the well and supported by spiders or overshot hangers anchored in the well casing below the upper ends of such lower flow conductors; and separate guide strings extending from the surface into the upper ends of each such lower flow conductor were required to direct the overshot connector into telescoping engagement over the projecting upper end of each such lower flow conductor for latching the upper tubing section and safety valve connected therewith in flow communication to the lower flow conductor. Also, in each case the control fluid conduit or conduits controlling actuation of the safety valves were each run into the well with the separate upper tubing section containing the safety valve to be controlled by means of such conduit. Thus, in prior installations, the upper tubing sections having the safety valves connected therein and control fluid conduits connected therewith were each separately installed and anchored to the upper end of a selected lower flow conductor supported in the casing below the surface of the well so that several trips and manipulative operations were required to complete the installation and ready the well for production.
In some of the prior types of installations, there was danger of disturbing the packers and the flow conductors in the well while effecting the installation and installing and removing the safety valves and upper tubing sections. In addition, in the past, there has been no provision of means for conducting lifting gas or treating fluid downwardly past a check valve and through a packer of such an installation nor for controlling flow into the annulus below a packer past a check valve which is wire line retrievable through the one of the flow conductors or tubing strings in which it is positioned for controlling the flow of lifting gas or treating fluid into the annulus exteriorly of the tubing string.
It is, therefore, one object of the invention to provide a new and improved method of and apparatus for treating and completing wells, either upon original installation or upon reworking, to provide surface controlled subsurface safety valves in the conductor or conductors of the well below the surface for closing off the flow from the well in the event of damage to the surface connections.
A further object is to provide such improved method and apparatus which is particularly adapted for use during initial completion of the wells or for use in reworking wells during recompletion.
A particular object of the invention is to provide a method of and apparatus for installing receptacles in a well in or above a packer or a hanger for receiving the lower ends of one or more upper flow conductor sections in flow communications with the well flow conductors extending downwardly in the well below the upper packer or hanger, and wherein the upper flow conductor sections may be installed in such receptacles without the necessity of separately running and pulling guide strings and the like.
An important object of the invention is to provide means for running multiple strings of upper flow conductor sections in multiple-zone wells in which the safety valve for each of the lower flow conductors is run at the same time as all other of the safety valves of the multiple flow conductors.
Another object of the invention is to provide a method and apparatus of the character described wherein the control fluid conduits for controlling actuation of the surface controlled subsurface safety valves may be run simultaneously with the safety valves or separately installed at a subsequent time.
A further object of the invention is to provide a method and apparatus of the character just described wherein the safety valves and the flow conductors may be run in by a single one of the upper flow conductor sections and the additional upper flow conductor sections run separately into the well and anchored in a scoop head landing nipple or receptacle connected with the safety valves therebelow already in place in the well, whereby each of the upper flow conductor sections may be installed separately so as not to require unusual or extra heavy duty equipment and without the necessity of running guide strings or the like.
A still further object of the invention is to provide a method and apparatus of the character described wherein the control fluid conduits for conducting control fluid from the surface to the safety valves anchored in place in the well may be installed in such a manner that one control fluid conduit may be operable to control all safety valves or separate control fluid conduits may be installed to provide individual control for each of the safety valves and wherein such safety valves may be separately or simultaneously controlled from the surface.
Still another object of the invention is to provide an apparatus for and method of injecting lifting gas or treating fluids through a well packer and/or hanger in an installation of the character described for use in gas lifting fluids from the well or for treating the producing formations, and in which the flow path of the injected lifting gas or treating fluid through the hanger and/or packer is separate from the flow conductors extending therethrough.
A further important object of the invention is to provide in an apparatus and method of the character just described one or more check valves in the injected fluid flow path through the packer for controlling back-flow of the injected fluids from the annulus below the packer through such injected fluid flow path to the annulus above the packer, and further wherein at least one of such check valves is removable through one of the upper flow conductors sections for service, repair or replacement without otherwise disturbing the installation.
A further object of the invention is to provide in a check valve installation of the character described, means for closing off the flow path for the injected lifting gas or treating fluid when the removable back flow check valve is removed from the flow path in which it is normally installed and operable.